Stratigraphy and depositional environments of the Upper Devonian Fenstermaker Limestone, Eureka County, Nevada

Graduation date: 1990The Upper Devonian Fenstermaker Limestone is a thickening-upward sequence\ud of interbedded sandy intrapelsparite and subordinate calcareous siltstone and mudstone\ud which averages 190 ft (58 m) thick in the northern Antelope Range. The Fenstermaker\ud Limestone is revised and restricted herein to include only those rocks above a basinal\ud shale sequence of the upper Denay Limestone and below the Mississippian Davis Spring\ud Formation, and replaces the names "Devonian sandstone" of Trojan (1978) and the\ud "Fenstermaker Wash Formation" of Hose and others (1982).\ud Sandy limestone of the Fenstermaker Limestone was deposited rapidly, above\ud upper Denay basinal shales, as resedimented beds in Frasnian Montagne Noir conodont\ud zone 13 and the Lower Famennian Middle triangularis Zone. Reworked conodonts are\ud present at numerous stratigraphic levels in the Fenstermaker, indicating erosion on the\ud inner or middle carbonate platform during two Upper Devonian eustatic regressions (in\ud lower and upper T-R cycle Ild; western U. S. events 7 and 8). Deposition of the\ud Fenstermaker Limestone was by allodapic sediment gravity flows on an outer-shelf-basin\ud ramp or at the toe of a low-angle (